1. Field of the Invention
The invention relates to a method of, and apparatus for, controlling spectrum use in a wireless communications system.
2. Description of the Related Art
Recent studies worldwide indicate that while some systems and mobile operators are in desperate need for more efficient utilization of spectrum resources, most of the radio spectrum resources remain underutilized or unused most of the time. The increasing demand for flexible use of the radio spectrum for emerging new services and applications is the motivation behind numerous research activities worldwide. Efficient access to radio spectrum resources will generate new sources of revenues for worldwide vendors and wireless network operators.
Four different levels of spectrum management techniques have been introduced in three different time scales: Spectrum Sharing and Coexistence (couple of hours or days), Long Term Spectrum Assignment (couple of minutes), Short Term Spectrum Assignment (1 sec or tens of ms) and fast dynamic spectrum allocation (10 ms time scale or even below).
However, due to the heavy traffic load, multiple negotiating parties involved in a Short Term Spectrum Assignment process might not be able to provide free spectrum to other parties, for the simple reason that they themselves require the spectrum.